The most common approach for stabilizing structural load bearing elements such as underground enclosures and their associated frames is to employ cementous grout. Even when quick setting cementous grout is employed for such purpose, a tremendous investment in labor and time is involved. For example, installation of quick setting cementous grout between an underground utility vault and its frame quite typically runs in the order of 4 to 6 hours. Then too, there is an extended set time before full traffic loads can be withstood. It is not uncommon for set time of quick setting cementous grout to run in the order of three days or more. Because of the long period of time between installation of cementous grout and load bearing set time, a crew will have to make a separate trip to the site to reopen the street or perform such other actions as may be necessary, again adding to the cost of the project.
Waste can also be a problem when cementous grout or other materials are mixed on site. In fact, loss is virtually bound to occur when typical techniques are employed to fill a void space between load bearing structural elements. Often too much grout or other similar material is mixed simply because it is difficult to estimate requirements. And, of course, when employing conventional approaches a good portion of the grout or other mixture regularly ends up where it is not required.